High temperature oxidation behavior of a novel Ni-Cr-W-Al-Ti superalloy. (15th April 2022) - Teng, Jianwei
Abstract: Oxidation of a novel Ni-19Cr-17W-2Al-0.5Ti superalloy was investigated in air at 800–1100 °C. In spite of the local spallation of external oxide scale after prolonged oxidation at high temperature, the alloy maintains excellent oxidation resistance. The excellent oxidation resistance is related to continuous external Ti-rich oxide covering on Cr2 O3 scale, which inhibits, at least to a certain degree, the evaporation of Cr2 O3 . In addition, this can also be ascribed to the fine Al2 O3 particles along grain boundaries of alloy matrix, which plays a key role in inhibiting the inward O diffusion and outward Cr diffusion through grain boundary. Highlights: Oxidation behavior of Ni-Cr-W-Al-Ti alloy was investigated. Alloy remains good oxidation resistance upto 1100 °C. The oxidation is dominated by Cr diffusion in Cr2 O3 . Ti-rich oxide inhibits the evaporation of Cr2 O3 . Al2 O3 in alloy matrix inhibits inward O diffusion and outward Cr diffusion.